Box loader



DeC- 5, 1967 J. L. ALDRED 3,356,238

BOX LOADER Filed Nov. 9, 1965 s Sheets-sheet 1 f V@ i 20 O f4 2 F76. 4/F/G.

J. L. ALDRED Dec. 5, 1967 BOX LOADER 3 Sheets-Sheet i Filed Nov. 9, 1965Arrazvzrs Dec. 5, 1967 J. ALDRED 3,356,238

BOX LOADER Filed Nov. 9, 1965 3 Sheets-Sheet .'5

Mm, am zum United States Patent O 3,356,238 BOX LOADER .lohn L. Aldred,Portland, Greg., assigner to FWD Wagner, Inc., Portland, Oreg., acorporation of Oregon Filed Nov. 9, 1965, Ser. No. 506,976 7 Claims.(Cl. 214-147) This application relates to a box loader.

For handling large boxes and particularly for lifting the box portion ofa semi-trailer to and from the wheels and supporting structure of suchtrailers, my device has flexibility and ease of handling far superior toany device known to me.

My device consists of a lifting unit having inner and outer liftingarms, each of which is provided with small lift fork portions extendingtoward each other. The arms are connected by an upper bridge unit, whichpermits the outer arm to swing with respect to the bridge unit andpermits the bridge unit to `swing with respect to the inner arm todisengage the lifting unit from the box to be lifted. Positive signalsare provided to inform the operator of the degree of engagement of thearms with the box. The entire lifting mechanism is able to tilt withrespect to a vertical plane and is able to move laterally to positionthe box longitudinally. In addition the entire unit may movelongitudinally to position the box laterally. The entire structure iscarried on an elevatable boom mounted on a tricycle tractor, which issteered by means of a single wheel at the other end of the tractor fromthe lifting unit for further exibility. The tilting capabilitycompensates for tilt induced by elevating the boom and fornon-parallelism between a surface on which the box is to be placed andthe surface on which the tractor is operating.

FIG. l is a front quarter perspective view of the device of myinvention.

FIG. 2 is a side elevational View 4of the device of my invention,omitting most of the tractor, and with portions of the boom broken awayto a longitudinal cross-section to show the internal structure. v

FIG. 3 is -a view on line 3 3 of FIG. 2 with portions broken away toshow the internal structure of the inner lift arm.

FIG. 4 is an enlarged fragmentary cross-sectional view on line 4-4 ofFIG. 3.

FIG. 5 is an enlarged fragmentary cross-sectional view on line 5 5 ofFIG. 3.

FIG. 6 is an enlarged fragmentary cross-sectional view on line 6*6 ofFIG. 3.

My device consists of a three-wheeled tractor 10 provided with a boom 11extending longitudinally from a pivot 12 between and beyond the pair ofwheels 13 at one end of tractor 10. Wheel 14 is steerable and is at theopposite end of the tractor from boom 11. Boom 11 is elevated aboutpivot 12 by cylinders 15. Carried at the end of the boom 11 bysupporting structure to be described later is an inner lift arm 20provided with lower lift fork portions 21, and an outer lift arm 30provided with lower lift fork portion 31. The outer lift arm 30 isspaced from the inner lift arm 20 by a bridge member 40. Bridge 40 ispivoted at 41 to the inner lift arm and at 42 to the outer lift arm. Ahydraulic cylinder 43 controls the pivoting of bridge 40 about innerlift arm 20, while a hydraulic cylinder 44 controls the pivoting ofouter lift arm 30 about pivot 42 with respect to bridge 40.

Bridge 40 is also provided with a generally hook-shaped stop member 45extending upwardly at an angle from the bridge member to engage the backof a cross member 22 which is part of inner lift arm 20. The engagementof hook 45 with cross member 22 when bridge 40 is in its horizontalposition provides assurance against lowering 3,356,238 Patented Dec. 5,1967 ice bridge 40 below the horizontal position and carries the loadimposed on lift arm 30 to beam 22. Bridge 40 is also provided with `astop 46 which engages a complementary stop surface 28 on inner arm 20,to restrict the lifting movement of bridge 40 to the maximum desiredposition.

As best shown in FIGS. 2, 3, 4 and 6, the device of my invention isprovided with a series of indicator flags to inform the operator wheninner arm 20, bridge 40, and outer arm 30 are in their proper positionswith respect to a box 16. The indicator for outer arm 30 mayconveniently consist of a plunger 32 pivotally connected to a bell-crank33 which is in turn pivotally connected to a push rod 34 extending thefull height of outer arm 30 where it is pivotally connected to a flag35, above the pivot point 36 between the Hag and outer lift arm 30. Theweight of rod 34 causes flag 35 to be normally retained in a horizontalposition, at the same time urging plunger 32 outwardly. If plunger 32 isengaged by the side of a box 16 it will be pushed inwardly, therebyrotating bell crank 33, raising rod 34, and erecting flag 35 to aposition where it will be visible to the operator of the tractor. Inthis manner the operator is informed that lift arm 30 is against theside of box 16 although he cannot see it directly. In the same manner,inner arm 20 is provided with a plunger 23 having a stem 24 which bearson a tab 25 of flag 26, so that when box 16 engages plunger 23 the flag26 is carried to an erect position about pivot 27, indicating that thebox is in full engagement with inner lift arm 20 (FIG. 4). The flag isnormally biased by gravity to a horizontal position. As best shown inFIG. 6, the stop hook 45 has a tab 47 which engages a plunger 23a havinga stem 24a. Plunger 24a is shown in FIG. 6 in the position in which ithas been urged inwardly against tab 25a of flag 26a to erect the flagabout pivot 27a, showing that hook 45 is in full engagement with crossbeam 22 and consequently forms a firm support to maintain bridge 4-0 ina horizontal position against the Weight carried by outer lifting arm30. Flag 26a is also normally biased by gravity to a horizontalposition.

When all three ags 35, 26, and 26a are raised, the operator knows thatthe box 16 is firmly engaged with both lift arms 20 and 30, and that thebridge 40 is in loadcarrying position. He is thus free to proceed tolift and maneuver box 16, which may advantageously be the box portion ofa semi-trailer.

A feature of my invention is the unusual flexibility with which theoperator can maneuver a box 16 carried by lift arms 20 and 30. Suchmaneuverability is extremely important in placing a box 16 on a trailerunder-carriage and is also of considerable assistance in removing such abox from an undercarriage and placing it on a railroad car.

Inner lift arm 20 has an outer box-like lower portion 29 containingroller tracks 50, 51, 52, 53, 54 and 55. An inner box structure 29a isprovided with pairs of rollers 56, 57 and 58 to carry the entirevertical and sideload forces imposed by inner arm 20, outer arm 30,bridge 40 and box 16, while these structures are moving laterally withrespect to the inner box 29a. Lateral movement is accomplished by ahydraulic cylinder 59 which is pivotally attached at 60 to an ear 61attached to inner box 29a.

Box 29a is pivoted on shaft 62 which extends through sleeve 63. Sleeve63 is a part of boom extension 70.

Boom extension 70 comprises a downwardly and forwardly extending portion71 which is fixed to sleeve 63 and a generally rearwardly extendingsection 72 which extends through an opening 17 in boom 11 and serves tostabilize the box lifting portions of the structure against side sway,`since portion 72 is wide enough to substantially lill the width of boom11 between the side plates 1S.

A cylinder '73 is pivotally connected at 74 to inner box 29a of innerlift arm 20 and controls tilting movement of the lift structure 20, 30and 40 about shaft 62.

Boom extension 70 is also provided with a generally horizontal slidingsupport member 75 which carries at least one rear upwardly projectingroller 76, which rolls on a track 76a secured to the side plates 18 ofboom 11. Extension 75 rests on a roller 77 below it at the outer end ofboom 11. Boom extension cylinder 78 is attached to boom 11 at one endand to slide 75 at the other end to urge slide 75 longitudinally in orout with respect to boom 11, carrying boom extension 7% and the entirelift structure 20, 30 and 40 with it. This allows the box 16 heldbetween lift arms 20 and 30 to be moved longitudinally with respect tothe tractor 10 (which will usually be laterally with respect to box).

Thus it will be seen that my device is capable of shifting asemi-trailer sized load in two dimensions horizontally, and is capableof lifting said load and of tilting the load, either to compensate forthe slight tilt induced by lifting or to set the load on a surface whichis not parallel with that upon which the tractor rests. The system isfurther provided with warning devices to inform the operator when allparts of the unit are in iirm engagement with the load, to permit safelifting. These systems are both eicient and simple. All of thesefunctions may be carried out without moving the tractor, and themovements thus provided are augmented by the use of a tricycle tractorwith rear steering so that the tractor can turn in a radiussubstantially equal to the wheel base if desired. This gives thecapability of adjusting the angle of the box 16 with regard to the placewhere it is to be set down, such as a semi-trailer under-carriage.

I claim:

1. A box loading device comprising an inner carrying arm havinghorizontally projecting lifting means, an outer carrying arm havinghorizontally projecting lifting means, a bridge pivotally linked to saidinner arm and to said outer arm, motor means adapted to swing said outerarm outwardly with respect to said bridge, motor means adapted to swingsaid bridge upwardly with respect to said inner arm, a tractor, andmeans mounting `said inner arm on said tractor for longitudinal,lateral, vertical and tilting movement with respect to said tractor.

2. The device of claim 1 in which said means include a longitudinal boommounted on said tractor to pivot about a point located generallycentrally of said tractor, motor means adapted to raise said boom withrespect to said tractor about said pivot point, and motor means betweensaid boom and said inner arm adapted to tilt said inner arm with respectto said boom.

3. The device of claim 1 in which said inner arm is comprised of aninner box and an outer box, said inner box being narrower than saidouter box, and rollers interconnecting said inner and outer boxes forlateral movement of said outer box with respect to said inner box, andmotor adapted to move said outer box laterally With respect to saidinner box, said boxes, rollers and motor constituting said means formoving said inner arm laterally with respect to said tractor,

4. The device of claim 1 in which said means include a boom and a boomextension, said boom extension being longitudinally slidably mountedwithin said boom, said inner arm being supported on said tractor bymeans of said boom extension.

5. The device of claim 4 in which said boom extension is provided with agenerally horizontally extending member within said boom, a rollermounted on said member and having a portion of its periphery above theupper surface of said member, a track within said boom, said rollerbeing engaged with said track, a second roller at the end of said boom,said horizontally extending member resting upon said second roller, anda motor mounted to move said extension longitudinally with respect tosaid boom.

6. The device of claim 1 in which the inner lift arm is provided with aplunger, a flag pivotally mounted on said inner arm in a positionvisible to the operator, said ag being biased to a normally horizontalposition, said plunger being mounted for axial movement with respect tosaid inner arm and having an end positioned to be moved axially by anobject as the object is positioned on said inner lift arm, said plungerbeing adapted in one position of axial movement to raise said flag to avertical position and being adapted in a second position of axialmovement to permit said ag to drop to a horizontal position under theinfluence of said bias, a second ag pivotally mounted on said outer liftarm in a position visible to an operator, said second flag being mountedon a pivot and being gravity biased to a horizontal position, a secondplunger mounted for axial movement in said outer lift arm, a linkageconnecting said second plunger to said second flag and adapted to raisesaid second flag to a vertical position in one axial position ofmovement and to permit said second flag to drop to a horizontal positionin another axial position of movement, a third flag pivotally mounted onsaid inner litt arm, said third flag being gravity biased to ahorizontal position, a third plunger mounted for axial movement andengagable with said third ag to move said third Hag to a verticalposition in one axial position of movement and to permit said third agto drop to a horizontal position in another axial position of movement,and means mounted on said bridge adapted to move said plunger axially toits flag erecting position when said bridge is horizontally disposed.

7. The device of claim 1 in which said bridge is provided with a stopengagablev with a portion of said inner lift arm and adapted to preventdownward movement of said bridge under the entire weight of said bridge,said outer lift arm, and a load on said outer lift arm.

References Cited UNITED STATES PATENTS 2,920,917 l/l960 Sheeham 214-147X 3,052,366 9/1962 Duncan 214-147 3,057,490 10/1962 Sauer 214-147 X HUGOO. SCHULZ, Primary Examiner.l

1. A BOX LOADING DEVICE COMPRISING AN INNER CARRYING ARM HAVINGHORIZONTALLY PROJECTING LIFTING MEANS, AN OUTER CARRYING ARM HAVINGHORIZONTALLY PROJECTING LIFTING MEANS, A BRIDGE PIVOTALLY LINKED TO SAIDINNER ARM AND TO SAID OUTER ARM, MOTOR MEANS ADAPTED TO SWING SAID OUTERARM OUTWARDLY WITH RESPECT TO SAID BRIDGE, MOTOR MEANS ADAPTED TO SWINGSAID BRIDGE UPWARDLY WITH RESPECT TO SAID INNER ARM, A TRACTOR, ANDMEANS MOUNTING SAID INNER ARM ON SAID TRACTOR FOR LONGITUDINAL, LATERAL,VERTICAL AND TILTING MOVEMENT WITH RESPECT TO SAID TRACTOR.